I have an old Craftsman 3/21 snow-blower (Model: 536.884581). The snow-blower starts perfectly, motor runs perfectly and the auger spins when the drive is engaged. When I use it to blow snow, it “sometimes” blows the snow out of the chute but later it stops blowing snow. I soon start seeing a lot of snow accumulating at the neck of the snow-outlet chute. I initially thought that the drive-belt was lose and hence tightened it. This did improve auger spin-rate but did not solve my problem I next checked on the internet and many folks suggested that the shear/cotter pin must have broken off in the auger-shaft. However, when I checked my unit’s underbelly, I did not see any shear/cotter pin on either side of the auger.

QUESTION: What corrective action (fix) should I take to make my Craftsman 3/21 Snow-blower throw/blow snow without collecting snow at the chute's neck?



  • 1
    what is your question?
    – jsotola
    Jan 24, 2020 at 3:18
  • 5
    "I did not see an shear/cotter pin" that's what it would look like if it was broken. Jan 24, 2020 at 3:36
  • 4
    Hold or immobilize the belt, then see if you can turn the auger. If so, look for a couple of holes on the auger that are 180 degrees apart. That's where the shear pin goes. The other issue I can think of is that you were trying to move wet snow. Your snowblower doesn't have the HP to deal with much of that so you'll have to proceed very slowly, letting the machine take small bites. If you don't the snow will quickly build up around the chute inlet and block it. You could try spraying the chute with Pam or one of the purpose-made snowblower chute spray lubes. Jan 24, 2020 at 13:39
  • Thanks "NothingToSeeHere"; Yes, the snow was wet (Chicago) and I did notice that it was sticking to the neck; I also checked once again for shear-pins and did not find any; nor did I find any holes (with broken shear pins). Given the situation (no shear-pins, no broken shear-pins, augur spins when motor is on, snow sticks), I believe your wet-snow reasoning is correct and on the money!!! So, I tightened the cable-adjustment-bracket; I am hoping that this will give the additional drive-power (HP) due to a tighter belt. If this works, I will replace it with a new belt.
    – user97485
    Jan 26, 2020 at 4:19

2 Answers 2


My Craftsman 3/21 single-stage, 2-stoke snow-blower now works perfectly and discharges snow from chute as expected/desired. Thanks to everyone that helped me solve this HI/DIY problem!!!

Corrective steps toward problem-resolution:

  1. Replaced drive-belt (specification was 35"; my old one had stretched out by over an inch)
  2. Replaced auger-blades (hard rubber) with new ones. The old ones were worn-out and were not (almost) sweeping past the backboard near the chute. The recommended gap is less than 1/4 inch. My old blade had a gap of almost 3/4 inch
  3. Sprayed snow/ice repellent near the neck of the chute to prevent ice build-up when dealing with wet-snow (as was the case today in Chicago).

BTW, I took this DIY opportunity to replace all screws & aluminum rivets with appropriate stainless steel nuts/bolts/washers. It costed me an additional $6; however, I thought that it will save me a lot of time when it comes time to do maintenance on my snowblower some time in the future ... especially since the screws get rusted quickly as snowblowers are mostly/often used in wet conditions and we (at least I) often do not take the time/trouble of wiping the snow-blower after using it (since it is too cold outside).


I was curious about this question and the comments suggesting the shear pin, so I entered the model number in a search engine that's usually been pretty Googd for finding things. If found a lot of links to scam downloads but not the manual. I went to another search engine that doesn't get as much play and Bingo it found the manual.

The manual does not mention a shear pin in the troubleshooting section under "Unit fails to discharge snow" and I did not see one in the exploded diagrams. So I think this snowblower may just depend upon the belt slipping when jammed.

The troubleshooting section only mentions clogs, the belt and the auger control cable.

Clogs are obvious, but an object jammed between the auger and the chute can be harder to see. But if the auger turns by pushing on it with a stick when off, you know it's not jammed.

If the belt is tensioned properly it's possible the belt got glazed, that is, when it was loose and slipping, its surface got polished and with less friction, it can no longer transfer much torque.

The auger control cable is my bet, make sure it's doing it's job, they do tend to slacken with vibration. If you can make the auger turn by pulling the cable with a pliers (carefully) it's not tensioned properly.


  • 2
    Thanks batsplatsterson!!! I conducted an additional test by “turning the auger after securing the auger control bar to the handle and the auger did turn. To further validate your theory, I changed the cable position in the “cable adjustment bracket” to the tightest level and could still rotate the auger relatively easily. Hence you are QUITE CORRECT that the belt is not tensioned properly. I’ll purchase and install a new belt (319596) as I agree with you that the belt is the root-cause!! However, I’ll have to wait until the next snowfall to confirm!
    – user97485
    Jan 26, 2020 at 15:59

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